The Original Series reading list lacks the
firmly established "Relaunch" that is the hallmark of the other series'
continuities. The majority of TOS novels are stand-alone, and most can
easily be read in any order. Some central storylines and stories can be
picked out however. Many recent TOS novels have included elements of
the wider Lit-verse, and several older novels have been repeatedly
referenced. In addition there are the novels that comprised the
"Original Lit-verse" of the 1980s. This was a group of stories which
were eventually linked together through references and shared
characters. Of particular importance to the later Lit-verse are the Rihannsu series and The Final Reflection,many elements of which have been more or less incorporated into the modern continuity, though undoubtedly requiring a certain amount of retcons.

The earliest book eventually connected to the "Original Lit-verse" was
published in 1981. The continuity was severely cut back around ten
years later under the direction of Gene Roddenberry and Richard Arnold.
A few references snuck through in the years following Roddenberry's
death, up until the advent of the modern Lit-verse. Closely connected
to these books were the DC Comics series of the 1980s. Characters where
sometimes shared between the two series. Several "Original Lit-verse"
novels have been referenced in the modern continuity, more or less
linking both bodies of work. The numbering system of the "Original
Lit-verse" included here is strictly chronological and did not originate
from the authors' or editors' intent.

There is also the "Byrne-verse" which is comprised of many of the comics of John Byrne published by IDW. These form a seperate continuity which has been linked to the Lit-verse by several references, but which doesn't completely fall within the same continuity. A few other IDW comics have referenced the Byrne-verse.

In addition to the references noted below,
several additional novels, short stories, comics, and audiobooks are
connected due to recurring characters and various references in other
books, or to other books. Other novels are connected by the five
crossover series Invasion! (which is referenced several times in the Lit-verse), The Captain's Table (which connects thematically with the Lit-verse spanning Tales From the Captain's Table), Section 31 (which ties into the DS9 Relaunch,) and Gateways (which ties into two Lit-verse series.)

Nine short stories or novellas are also connected, five from Enterprise Logs (which references several Lit-verse novels), two from DS9: The Lives of Dax (which ties into the DS9 Relaunch,) one from The Brave and the Bold duology (which ties into the Gorkon series,) and one from Seven Deadly Sins (which ties into three Lit-verse series.) Three novels and one ebook in other series cross over with TOS- DTI: Forgotten History, VAN: Harbinger, VAN: Storming Heaven, and VAN: In Tempest's Wake.

Also included are the stories from Constellations (one story of which is referenced in TNG: Before Dishonor), and Mere Anarchy (which references several stories.) Various references in parts of the Marvel Untold Voyages series, IDW's New Visions: Issue #5, the Wildstorm Star Trek Special, the DC Series 2 Special #2, and the anthology New Worlds, New Civilizations connect
TOS stories from those works. The TOS reading list stops at the
disappearance of James T. Kirk aboard the Enterprise-B and all
storylines transfer to "The Lost Era", the Early 24th Century Reading
List.

(Note that the covers of many TOS books contain
models of the Enterprise or uniforms which do not match the era of the
book, and which sometimes do not even match each other. These should be
disregarded.)

Dark blue denotes the primary narrative. Read
these for the works most closely linked to the Lit-verse. Light blue
denotes the expanded storyline. Read these for other works closely
connected to the Lit-verse. Dark green denotes the Original Lit-verse.
Light green denotes the DC Comics continuity. Purple denotes the John Byrne continuity. Many stories cross
between two or more of these categories, and the categories themselves,
in the case of TOS, could be flexible. The white denotes every
other connected story from the entire Lit-verse. Hover for notes.